Transmission



De.26,1967 .H QSCHJOUN TAL 3,359,832

TRANSMISSION Filed Jan. 6, 1966 2 Sheets-Sheet l OVT/U7 T FILTERATTORNEY DeC 26, 1967 Hf o. SCHJOLIN ET A1. 3,359,832

TRANSMISSION Y Filed Jan. e, 1966 2 sheets-sheet 2 ATTORNEY UnitedStates Patent O 3,359,832 TRANSMISSION Hans 0. Schjolin, Birmingham, andLuther N. Kern,

Berkley, Mich., assignors to General Motors Corporation, Detroit, Mich.,a corporation of Delaware Filed Jan. 6, 1966, Ser. No. 519,103 6 Claims.(Cl. 74-781) This invention relates to transmissions and control systemstherefor yand particularly to drive con-trols employing alternativelyoperable dual friction engaging devices.

The invention is employed in transmissions having a pair of frictiontorque establishing devices, such as brakes or clutches, which areemployed to establish the ratio drives wherein one of the devices isspring applied and `a fluid motor is used to release the one device andapply the other device to change the ratio of the drive. In this type ofarrangement, where the motor is stationary and the friction torqueestablishing devices and the spring rotate 4at times, it is desirable tomaintain on the transfer bearing connection between the motor and thespring a suilicient load to insure relative rotation at the bearing andnot between other elements of the connection. Thus the tmotor isconstructed to provide in the release position a small residual forceacting against the spring to provide this load on the transfer bearingbut insuilicient to release the spring applied device and apply theiluid -applied device. For motor apply, a large iluid force is providedto release the spring applied device and engage the lluid applieddevice. In the specific embodiment this is accomplished by applyinglubricating oil at a low pressure to the apply side of the motor and areduced lubricating oil pressure to the other side of the motor toprovide a small release force suicient to insure relative rotation atthe transfer bearing surface. In order to apply the fluid applieddevice, the lubricating oil pressure is disconnected from the apply sideand a substantially higher line pressure is connected to the apply sideto apply the fluid applied device.

An object of the invention is to provide in a transmission having aspring applied and a pressure applied friction torque establishingdevice and a fluid motor connected through an apply spring by a bearing,the motor providing a small apply force merely to load the bearingssuillciently to provide for rotation at the bearing surfaces and ahigher force to release the one device and apply the other device.

Another object of the invention is to provide in a transmission having aBelleville spring applying a rst friction torque establishing device anda second friction torque establishing device applied by the Bellevillespring when moved to the release position, a iluid motor connected by athrust transfer bearing to the Belleville spring and controls to supplythe constant release fluid pressure to the release chamber of the iluidmotor and la slightly higher pressure to the apply chamber of the iluidmotor when the spring is engaging the rst friction torque establishingdevice and to Iapply a high pressure to the apply side of the fluidmotor to release the -frst device and engage the second device.

These and other objects of the invention will be more apparent from thefollowing drawing and description of the preferred embodiment.

FIGURE 1 schematically shows the transmission gearing and controlsystem.

FIGURE 2 shows a portion of the transmission gearing arrangement and theactuating mechanism therefor.

The transmission drive train -as illustrated in FIGURE 1 has a two-speedsplitter input unit 10, a bevel drive unit 11, a converter drive clutch,direct drive clutch and torque converter assembly 12 and a forward andreverse output drive 14. The input shaft 16, or'engine shaft,

drives a flywheel 17 which is drivingly connected through the driveplate 1-8 to drive the carrier 19 which has planetary pinions 21 meshingwith the ring gear 22 drivingly connected to the intermediate orsplitter output shaft 23 and a sun gear 24 connected to the sun gearsleeve shaft 26. A clutch drurn 27 is secured at a middle point to thesleeve 26 so that the center of the drum is substantially concentricwith the sleeve shaft bearing 28. The splitter 10W or direct driveclutch 30, when engaged by the Belleville lever spring 31, when thefluid motor 32 is released, connects the sun gear and the ring gear tolock up the gear unit for direct drive or low. The brake 33, whenengaged by motor 32 acting through spring 31, connects the sun gear 24to the grounded portion or cylinder 34 of motor 32 to retard the sungear for high or overdrive. The arrangement of these components isdescribed below with reference to FIGURE 2.

The splitter output shaft 23, supported at the rear end by a bearing 36,is connected by the bevel gear unit 37 to drive the angle drive inputshaft 38 mounted in bearings 39 and 41 supported on the housing and theconverter and direct drive clutch drum 42. The drum 42 is connected bythe clutch 43 when engaged by the motor 44 to drive the direct drive hub46, which drives the intermediate shaft 47, which is supported by abearing 48 between the sleeve shaft 38 and a rear bearing 49 on thehousing. The drum 42 also drives through the converter clutch 51,actuated by motor 50, the converter clutch hub 53 which is splined tothe converter input shaft 54 which drives the pump P of the torqueconverter. 'I'.he clutches have a common backing plate 45 fixed to drum42. A bearing 56 between the hubs 46 and 53 supports the end of shaft 54and locates the direct drive clutch hub. This clutch structure isdescribed in further detail with respect to FIGURE 2.

The torque converter pump P drives iluid in a toroidal path in theoperating chamber 57 to drive the turbine T1T2 which is connectedthrough a hub 58 and a one-way clutch and bearing unit `59 to drive theintermediate shaft 47 in on direction and to support the intermediateshaft. The stator blades S are secured to the xed housing 60 and providereaction in the torque converter. The forward or pump end of the pumpshaft 54 is supported to the fixed housing by a bearing l61. 'I'hebearing 62 supports the turbine assembly on the shaft 54.

The shaft 47 drives the output gear 71 and clutch teeth 7.2. The outputshaft 73 has splined thereon a gear 74 for axial movement so that theclutch teeth 76 engage the clutch teeth 72 for direct drive and the gear74 engages the gear 77 driven from the reversing idling gears 78-79 toprovide reverse drive.

Hydraulic system The input driven pump 91 draws tluid from a sump 92located in the base of the transmission housing and supplies fluid tothe main line 93 at a pressure regulated by the main line regulatorvalve 94 which exhausts the normal overage to the converter feed line 96and the lubribation line 97 and has an exhaust 98. The pressure in theconverter feed line is regulated by the converter pressure regulatorvalve 101 which exhausts the overage via exhaust line 102 to sump. Theconverter feed line 96 is connected through a illter 104, a check valve105 for a one-way feed to the converter operating chamber 47. A governor107 supplied with fluid from the main line 93 is driven through shaft108 at a speed proportional to the speed of the output shaft 73 andprovides in governor line 109 a pressure proportional to vehicle speedor output shaft speed.

A splitter shift valve 111 controls the supply of main line fluid andlubricating fluid to the double acting motor 32 to control the operationof the splitter low and splitter high motors. This value has a valveelement 112 having lands a and b of small diameter and a larger land clocated in a stepped bore 113 and is biased toward the downshiftposition by spring 114. In the downshift position the valve112.1connects'the lubrication line 97 to the apply line 116. Thelubrication line is also connected by branch117 to the releasechamberwhich has a restricted exhaust 118 to lubrication line 119 (FIG. 2) tocontinuously vent the release chamber and thus maintain a lowervpressure acting on the larger area of the release side of the piston toprovide a biasing force to almost balance the higher lubricatingpressure acting on the smaller area of the apply side of the piston, butto provide a small residual force to the right in FIGURE 1 or the applydirection which keeps the transfer bearing engaged, so relative movementis between the rollers and races of the thrust bearing 212, FIG. 2, andnot between the race and snap ring or the race and the spring. When thespeed increases sufficiently to provide a governor pressure to upshiftthe shift valve, the valve will, in the upshift position, connect mainline 93 to apply line 116 to move the motor 32 to engage the high brake.The lubrication branch line 117 has restricted branches 121 to lubricatethe splitter gear unit, the bevel gear 37 and the reverse gear unit 14.

The direct drive and converter drive clutches are controlled by a relayvalve 126, a manual valve 127 and an automatic shift valve 123. Therelay valve 126 has a valve element 131 having lands a and b of equaldiameter located in a bore 132 and biased in the open position by spring133 and closed when fluid is supplied to the chamber 134. This valve inthe open position shown, connects the main line 93 to the transferpassage 136 leading to the manual shift valve 127. The manual shiftvalve has a valve element 141 having lands a and b of equaldiameterlocated in the bore 142, and is actuated by a solenoid 143,which in the current o position shown, connects transfer passage 136 tothe converter clutch apply line 149, which supplies fluid to theconverter drive motor 50 to engage the converter clutch 51. In thesolenoid on position, partially shown in the dotted lines, passage 136is blocked and the converter clutch apply line 149 is connected betweenthe lands to the branch 151 of the direct drive apply line 151. The endsof the bore 142 are vented by exhausts 152 and 153.

The shift valve 128 has a valve element 156 having lines a and b locatedin a bore 157 and is biased to the lclosed or downshift position forconverter drive as shown by the spring 156. The spring chamber end ofthe bore is vented by exhaust 158 to prevent fluid accumulating andinterfering with the action of the valve. With the valve in thedownshift position, the direct drive clutch Valve line 151 is connectedto exhaust 159 disengaging the direct drive clutch to place thetransmission in converter drive.

When the pressure in the governor branch line 161, acting on the end ofland b of valve element 156, increases suiciently to overcome thebiasing force of the spring 156', the valve moves to the upshiftposition connecting main line 93 to direct drive clutch apply line 151blocking exhaust 159. The fluid supplied to the direct clutch apply line151 and motor 44 flows through the restriction 162 to line 163 which isconnected to the accumulator 164 and the chamber 134. The pressure inline 163 rises slowly due to the restricted feed and the increasingvolume of the accumulator 164 and when it reaches the pressure at whichthe direct drive clutch 43 is substantially engaged, the pressure inchamber 134 downshifts valve 126 to cut off the supply of main linefluid to transfer passage 136 and the converter apply line 149. Theaccumulator 164 has a springr164 in the vented end of bore 165 whichbiases the piston 165 to the closed end of the bore which is connectedto line 163.

For neutral drive, the switch 166 is closed to connect the battery 167to energize the solenoid 143 toplace the valve 127 in the on positionwhere the converter apply line 149 will be connected via the directdrive apply line 151 and branch 157 to exhaust 159 at the shift valve128. It will be seen that under these conditions, if the vehicle iscoasting at a high speed to upshift the shift valve 123, both clutcheswould be engaged for increased braking. A manual forced downshift isprovided by a downshift switch 171 which is closed when thethrottlepedal is in the full trottle position to actuate a normally opened valve172 to block the flow from the governor in line 161 and exhaust line 161only downstream of the valve 172 via port 173 in the valve to exhaust174.

The direct drive clutch 30 and overdrive brake 33 are located in thehousing or drum 27 as shown in detail in FIGURE 2. The clutch 30'hasplates alternately splined to the outer drum 27 and the drum portion 201of hub 202, which has an inner sleeve 203 splined to the splines 204-onshaft 23. It will be noted that splines 204 are concentrically withinthe brake 33 and that the sleeve 203 is spaced from the shaft 23 formore than half the length of thedrum 27 so that the sun gear sleeveshaft 26 which supports both sun gear 24 and the drum 27 may extendbetween the sleeve shaft 203 and shaft 23 to a point substantiallycentrally within the drum 27, where shaft 26 is supported `by bearing 28on shaft 23. The L-shaped piston 206 has a cylindrical portion 207surrounding sleeve 203 in sealing engagement therewith and an annularportion 208 extending radially nad having its periphery 209 in sealingengagement with the inner cylindrical surface of the fixed cylinder 34.Cylinder 34 also has an inwardly extending annular portion 211 meetingin sealing engagement the outer surface of the sleeve portion 207 ofpiston 206. Thrust is transferred from piston 206 via the thrust bearing212 which -consists of a pair of plates with needle bearings between theplates. One plate is axially located on the sleeve 207 by suitablemeans, such as a snap ring, and the other plate bears against the innerperimeter of the Belleville lever spring 31. The outer perimeter ofBelleville spring 31 is pivotally mounted on the inner surface of thedrum 27 by suitable means, such as snap rings 216. The Belleville spring31 is formed to normally spring'bias pressure plate 221, which has asuitable pivot ring thereon, to engage the plates of the direct driveclutch 30. As explained above, when the spring is in this position, theresidual force provided by full lubrication pressure on the apply sideand reduced lubrication pressure on the release sideengages the thrustbearing just enough so relative movement is between the races androllers and not between one race and the snap ring or between the otherrace and the spring. When main line pressure, which is higher thanlubrication pressure, is admitted to the uid motor 32, the piston actsthrough the thrust bearing to move the Belleville spring to disengagethe direct drive clutch and engage the pressure plate 222 at its pivotto engage overdrive brake 33.

The angle drive input shaft 38 drives the converter and lockup clutchdrum 42. The clutch 43 has plates alternately splined with the drum 42and the drum 226 which is mounted on the hub 46. The hub 46 also has acylindrical portion 227 of intermediate diameter to receive the bearing56 and a mounting sleeve portion 228 splined to the intermediate shaft47. The motor 44 has a cylinder 231, formed in the end wall of drum 42,which receives a piston 232. When fluid is supplied to the cylinder 231,the piston 232 engages the clutch 43 to connect the input driven drum 42via hub 46 to drive the intermediate shaft 47. The converter clutch 51has alternate plates splined to the drum 42 and the drum 233 of the hub53. The hub 53 has an inner cylindrical part 234 engaging the innerdiameter of bearing 56 and is splined to the pump input shaft 54. Theconverter drive clutch motor 50 has a cylinder 236, formed in the endwall of drum 42, to receive the piston 237. On the supplyA of fluid tothe cylinder 236 the piston 237 engages the plates to engage clutch 51for drive from the drum 42 to the torque converter pump shaft 54.

Fixed housing 60 has a sleeve extension 238 extending to the centralportion of the drum 42 where it supports a bearing 239, which engagesthe sleeve 241 which is fixed to the drum 42 to rotatably support thedrum 42. The fiuid transfer bushing 242 is located between the sleeve238 and sleeve 241 to transfer both the direct drive clutch supply lineand the converter clutch supply line from the fixed housing 60 to therotating drum 4Z for connection to the motors as shown diagrammaticallyin FIGURE 1. It will be noted that the drum 4Z is supported for rotationat each end by bearings 41 and 239 to the fixe-d housing. The clutchhubs 46 and 53 are aligned and centrally supported within the housing bythe single bearing 56 and centrally mounted on shaft 54- which issupported by bearings 48 and 62. Bearing 48 is closely supported byshaft 38 and bearing 41 to the fixed housing. Thus both the hubs arerotatably supported with respect to drum 42 by the bearing 43 which alsosupports the drum.

We claim:

1. In a transmission, drive means operative to establish a first and asecond ratio including a first friction torque establishing means forestablishing one ratio and a second friction torque establishing meansfor establishing a second ratio, means for selectively engaging saidfirst and second friction torque establishing means including springmeans rotatable at times and operative to normally engage said lirstfriction torque establishing means to engage said friction torqueestablishing means and stationary motor means operatively connected tosaid spring means by a transfer bearing and operatively connected tosaid second friction torque establishing means, and control means tosupply fluid pressure to said motor means to preload said thrust bearingmeans sufficient to load said transfer bearing for rotation only at thebearing surfaces but insufficient to compress said spring means and inanother selective position to supply a pressure to said motor meansapply chamber to move said spring means to disengage said first frictiontorque establishing means and to engage said second friction torqueestablishing means.

2. The invention defined in claim 1 and said control means supplying alow pressure to said motor means to preload said transfer bearing and ahigh pressure to move said spring means to disengage said first frictiontorque establishing means.

3. The invention defined in claim 2 and said motor means having arelease chamber continuously supplied with fiuid at a lowest pressureand exhausted to cool a friction torque establishing device.

4. The invention defined in claim 1 and said first and second frictiontorque establishing devices having apply plates located adjacent eachother, said spring being a Belleville spring located between said applyplates and normally engaging said first friction torque establishingdevice.

5. The invention defined in claim 4 and said Belleville spring beingannular and said motor having a piston sleeve extending through saidannular Belleville spring and said transfer bearing being locatedbetween said Belleville spring :and a ring secured to the end of saidpiston sleeve.

6. The invention defined in claim 1 and said drive means having input,output and reaction elements, said first friction torque establishingmeans being a clutch connecting said output and reaction element androtating when engaged, said second friction torque establishing meansbeing a brake and connected to said reaction means to hold said reactionmeans when engaged, said friction torque establishing means having applyplates facing eachL other, said spring being an annular Bellevillespring located between said apply plates and biased to engage saidclutch, said motor means having an L-shaped stationary annular cylinderlocated Within said brake and an L-shaped annular piston in saidcylinder defining an apply and release chamber having a larger areaextending through said spring, and said transfer bearing being locatedfreely between a ring on the end of said piston and said spring on theside remote from said cylinder, said control means including a source oflow pressure, a source of high pressure, said source of low pressurebeing continuously connected to said release chamber, a vent means insaid release chamber to cool said brake and to maintain the pressure insaid release chamber lower than said low pressure, a shift valveselectively connecting said low pressure to said apply chamber topreload said transfer bearing being just enough to insure relativerotation at the bearing surfaces and not between the races and the ringand spring and connecting said high pressure to said apply chamber tomove said spring to release said clutch and apply said brake.

References Cited UNITED STATES PATENTS 3,038,575 6/1962 Hansen 192--853,090,257 5/19631 Schjolin et al. 74-781 3,182,528 5/1965 Lamburn 192-18X DONLEY J. STOCKING, Primary Examiner.

THOMAS C. PERRY, Examiner.

1. IN A TRANSMISSION, DRIVE MEANS OPERATIVE TO ESTABLISH A FIRST AND ASECOND RATIO INCLUDING A FIRST FRICTION TORQUE ESTABLISHING MEANS FORESTABLISHING ONE RATIO AND A SECOND FRICTION TORQUE ESTABLISHING MEANSFOR ESTABLISHING A SECOND RATIO, MEANS FOR SELECTIVELY ENGAGING SAIDFIRST AND SECOND FRICTION TORQUE ESTABLISHING MEANS INCLUDING SPRINGMEANS ROTATABLE AT TIMES AND OPERATIVE TO NORMALLY ENGAGE SAID FIRSTFRICTION TORQUE ESTABLISHING MEANS TO ENGAGE SAID FRICTION TORQUEESTABLISHING MEANS AND STATIONARY MOTOR MEANS OPERATIVELY CONNECTED TOSAID SPRING MEANS BY A TRANSFER BEARING AND OPERATIVELY CONNECTED TOSAID SECOND FRICTION TORQUE ESTABLISHING MEANS, AND CONTROL